Burglar-alarm



A. W. DECROW.

Burglar Alarm.

No. 51,511. Patented Dec. 12, 1865.

WIT/V555 UNITED STATES PATENT OFFICE.

A. W. DEUROW, OF BANGOR, MAINE, ASSIGNOR TO EDMUND HOOLE, OF BROOKLYN, NEW YORK.

BURGLAR-ALARM.

Specification forming part of Letters Patent No. 5] ,511, dated December 12, 1865.

To all whom it may concern:

Be it known that [,A. \V. DECROW, of Bangor, in the county of Penobscot and State of Maine, have invented certain Improvements in Burglar-Alarms; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which Figure 1 is a vertical elevation, showing the internal construction of the apparatus. Fig. 2 is a side view. Fig. 3 is a front view, representingthe invention as applied to a window. Fig. 4 is a front view, representing the invention as applied to a door. Fig. 5 shows the shape of a small metallic plate used in connection with the invention in applying it to doors.

The object of this invention is to produce a burglar-alarm which can be applied with equal facility to either doors or windows; and it consists in certain novel arrangements of the tripping-bolt. with regard to the striking mechanism ot' the apparatus, whereby the desired object is etfected.

In order to enable those skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

The hammer a strikes upon the hell 0, and is attached atits lower end to therockingpivot "n of the pallet c, which receives a rocking motion from the toothed wheel (I, rotated by the cog-wheel b, which is revolved by the coiled spring D. This part of themechanismis similar to an ordinary clock-movement.

E is a bar pivoted at its rearmost end to the frame A, and having its edges'turned over, so as to form a sort of tube, in which the tripping-bolt B may be moved to and fro. c is a spring, which acts upon the bar E to press the tripping-bolt downward and sidewise, so that it rests in the corner 2' of the hole through which its end passes in the side of the frame A. r is a stout wire that extends upward from the pivot of the hammer, with its upper end resting agaist one side or the other of a short spur, s, which projects downward from the forward end of the bar E in such a way that when the tripping-bolt is moved upward or to one side the wire 1' will he released from the said spur and the hammer allowed to strike upon the bell. The bolt B is, of course, narrower than the hole through which it passes, in order to allow its lateral movement. The hole itself is extended upward, in order that the end of the bolt may be elevated when applied to windows, as will be presentlyexplained. A pivoted plate, m, prevents theboltfrom thus rising when the device is attached to doors.

Now, then, in using this apparatus upon a door it is secured atone edgethereof byscrews passing through the caseA. Byinsertingthe finger in the opening in the said case the bolt B is pushed inward, so that its end is flush with the side of the case, and the pivoted plate m is turned down over the bolt to prevent its rising. The separate plate F (shown in Fig. 5,) is then placed between the door anditscasing, the spurs 1; being forced into the said casing to hold the plate in place. The trippingbolt B is then pushed outward, its end entering the uppermost notch, a, in the plate F. It will thus be seen that the end of this tripping-bolt is held stationary when an attempt is made to open the door, and the door, moving slightly upouits hinges, will movethe case A sidewise with regard to the end of the bolt B, and thus cause the spur sto releaseits hold upon the end of the wire T. On this the hammer strikes the bell and sounds the alarm.

In applying the alarm to a window the tripping-bolt B is pushed outward, its end projectin g beyond the edge of the sash, the plate m is turned aside to allow the end of the bolt to rise, and a pin, it, is inserted in the sash immediately below the projecting end of the tripping-bolt B. When an attempt is made to raise the sash this pin to elevates the bolt and releases the wirer, thus sounding the alarm in the same manner as just hereinbefore set forth.

What I claim as my invention, and desire to secure by Letters Patent, is-

The tripping-boltB, so arranged with ref; erenee to the striking mechanism as to operate in either a vertical or horizontaldirection,substantially as herein set forth, for the purpose specified. .7

A. W. DEOROW. Witnesses:

F. A. WILSON, ANSEL LENNAN. 

